Random select from a string array

[jchd]

Slowness is essentially inherent to randomization of a significant number of [whatever] items. The few good (in some widely accepted sense) pseudo-random number generators (PRNGs) invariably rely on non-trivial mathematical algorithms which need time to compute. That's why physical true RNG are used in demanding applications, until a formidable mathematical discovery renders them unattractive, but that's unlikely to happen any time soon.

Never, ever try to come up with one homebrew PRNG: it will always be weeker (predictable) or have an much worst distribution than state of the art algorithms. Both AutoIt' and SQLite' random() functions are good enough for most purposes except for serious security applications, where more scrutiny will be required.